The present invention relates to a telephone attachment which permits the user to select from a variety of indicating signals. The classic method for indication of an incoming telephone call has been the electromechanical bell. More recently electronically driven sounding devies--tone ringer--shave begun to replace the bell. Both methods tend however to jar the listener into immediate attention or to abruptly disturb a conversion.An alternate signaling means would frequently be desirable. It is often found that a musical passage or chimes are a gentler method for drawing attention to an incoming call. In other cases the user might prefer some novel sound rather than the conventional pulsed ring. A short voice message, the sound of a waterfall or a flashing light display would be examples of alternate summoning signals which would be desirable or advantageous for certain telephone locations.
It is one objective of the present invention to provide a telephone attachment which will permit a number of output devices to be readily operated from the present ringer signal.
It is a second objective of the present invention to be operable from an internal battery and to operate an output device from the same battery. This will make the invention useable with telephones which are not located near power receptacles.
It is a third objective of the present invention to incorporate a low-battery voltage detection circuit which will switch off the output device and switch in a low current,audio signal source to respond to incoming calls and thus to indicate that the battery needs to be replaced.
It is a fourth objective of the present invention to provide a convenience switch to permit the return of the system to conventional operation of the telephone.
These and other objectives will be explained with reference to FIGS. 1 and 2.